Congenital adrenal hyperplasia (CAH) denotes a family of inherited disorders with defects in the cortisol biosynthesis. CAH has been traditionally considered a disease restricted to the adrenal cortex. However, recently observed abnormal adrenomedullary structures in three adrenalectomized patients with classic CAH, as well as low baseline urinary and plasma epinephrine levels in children with CAH suggest that this condition is associated with marked morphological and functional abnormalities of the adrenal medulla.